Ginseng for the Common Cold?

Drugs promising a cure for the common cold abound usually draw a
healthy skepticism, but one drug - COLD-fXÂ®- is now
surprisingly well backed up by a clinical trial.

In a peer-reviewed double-blind clinical study, COLD-fX (which
contains an extract of North American ginseng) was tested for its ability to
prevent upper respiratory tract infections. The study was published in
the Canadian Medical Association Journal and reported by Time
online's The Daily RX.

Clinical Trial Results

Researchers Predy et al. wrote, "Upper respiratory tract
infections are a major source of morbidity throughout the world.
Extracts of the root of North American ginseng (Panax
quinquefolium) have been found to have the potential to modulate
both natural and acquired immune responses.

"We sought to examine the efficacy of an extract of North
American ginseng root in preventing colds."

The randomized, double-blind, placebo-controlled study included
323 adults, aged 18-65 years, and was conducted over four months
during winter 2003-04 (the height of influenza season). Participants had a
history of at least two colds in the previous year and were
recruited from the general population in Edmonton, Alberta.

Participants took were instructed to take two capsules daily of
either the North American ginseng extract or placebo over a
four-month period. The primary outcome-measure was the number of
Jackson-verified colds, and secondary outcome-measures included
symptom severity, duration of symptoms, and duration of colds.
Participants scored their cold symptoms using a 4-point scale.

Results showed that participants who took COLD-fX had 25% fewer
upper-respiratory infections, compared with those taking placebo.
Moreover, those who developed infections reported lower symptom
severity, on average.